Gaseous electric discharge device



Feb. 5, 1935. H. A. w. KLINKHAMER ET AL 1, 9

, GASEOUS ELECTRIC DISCHARGE DEVICE Filed Dec. 1,. 1952 InvenforsHendrikAW Klinkhamer AarT deBr'uin Fer-clinandus H.A.vcm sfekelenbuwzgTheir Afl'orney GASEOUS ELECTRIC Hendrik A.

Ferdlnandns H. A. hoven, Netherlands, tric Compa y,

$ PATENT oFFIc mscnanae DEVICE W. Klinkhamer, Aart de Brain, and I vanStekelenburg, Eindassignors to General Elec-, a corporation of New YorkApplication December 1, 1932, Serial No. 645,284

Inthe Netherlands December 2, .1931

3 Claims. (Cl. 176-124) The present invention relates to gaseouselectric discharge devices generally and more particularly the inventionrelates to starting and operating circuits for such devices. l

The object of the present invention is to pro-'; vide an illuminatingsystem for roads, or the like. Another object of the invention is topro-. vide a very eflicient illuminating system which is inexpensive tomake and to install. Further objects and advantages attaching to thedevice and to its use and operation will be apparent to those skilled inthe art from the following particular description and from the appendedclaims.

, It is known in the art that gaseous .electric discharge devices.having a thermionic electrode require a higher voltage to start thedevice into operation than to maintain the device in "operation. Theexcess voltage supplied to the device duringthe operation thereof isabsorbed by an impedance connected in series with the gaseous electricdischarge device. In prior devices this series impedance has been aresistance or an inductance which absorbed all the excess voltage. Inthe present invention at least 50 per cent of the excess voltage isabsorbed in the current supply leads of the electric discharge devicewhich makes it possible to use a smaller and cheaper resistance orinductance in the supply circuit to reduce the cost of the illuminatingsystem. The current supply leads for the gaseous electric dischargedevice are smaller in diameter than prior supply leads for similardevices to obtain the desired result. This reduces further themanufacturing cost of the illuminating system and also reduces theinstallation cost of such a system. The greater the percentage of theexcess voltage absorbed in the current supply leads the greater will bethe saving in the manufacturing and installation cost of the system butin practice it is advisable to absorb approximately 50%-90% of theexcess voltage in the supply leads of the gaseous electric dischargedevice. The excess voltage not absorbed by the current supply leads inany particular instance is absorbed in a small, inexpensive, seriesconnected resistance, which is preferably a variable resistance, toregulate the value of the'total resistance connected in series with thegaseous electric discharge device.

The new and novel use of the current supply leads of the electricdischargedevice is of great value where a plurality of series connecteddevices separated cdmparatively large distances are used to illuminateroads, for example. The leads connecting the devices in series, if madein accordance with the present invention, are smaller and cheaper thanwould be practical if they were not used as part of the series connectedimpedance for the device which, of course, lowers the manufacturing andinstallation costs of the system to a minimum.

I have found that auto-transformers are the most emcient, most practicaland least expensive transformers for use in my new and novelilluminating system. Such transformers, when used in the seriesconnected system distribute the voltage throughout the system in a veryadvantageous manner. When the series connected discharge devices are ofthe type having a thermionic electrode at each end thereof the two leadsfor each electrode are connected to a small section at the respectiveends of said transformer and the mid-part'of said transformer betweensaid sections is made of smaller and cheaper wire to eflect a greatsaving in the manufacturing cost of the transformer. This is entirelypractical as the mid-part of the transformer, in this case, is not.traversed by the operating current.

In the drawing accompanying and forming part of this specificationseveral embodiments of my invention are illustrated in which Fig. 1 is aschematic view of one embodiment of my invention,

Fig. 2 is a similar view of another embodiment and view of anotherembodiment of my invention,

Fig. 3 is a similar of my invention.

Referring to Fig. l of. the drawing the illuminating system comprises aplurality of gaseous electric discharge devices comprising a container 1having a gaseous atmosphere therein of a rare gas, a metal vapor, or amixture of a rare gas, such as neon, and a metal vapor, such as sodium.Two thermionic electrodes 2, 3 and 2, 3 are sealed into saidcontainer 1. Said electrodes comprise a metal cylinder 2, such as anickel cylinder and a heating iilament'3 inside said cylinder. Theexterior walls of said cylinder are coated with an electron emittingmaterial, such as barium oxide. The heating filaments 3 and 3 of saidelectrodes 2, 3 and 2, 3 are connected in series by lead 21 and thecylinders 2 and 2 are connected to the current supply leads for saidfilaments 3 and 3 by leads and 20, as shown. The electric dischargedevices are connected in series to the secondary of the transformer 5 byleads 4 and 4. The primary of said transformer 5 is connected to theterminals of an alternating current source. when current is applied tothe above circuit the cylinders 2 and 2 are promptly brought to anelectron emitting temperature by heating filaments 3 and 3. As soon assufficient electrons have been emitted into the discharge path anelectric discharge is established between said electrodes 2, 3 and 2, 3.During the operation of the device each of said electrodes actsalternately as anode and cathode. I

During the operation of the devices the excess voltage supplied to saiddevices is absorbed by the current supply leads 4 and 4 which are ofsuch diameter and length that they act as the series connectedresistance. This function of the conductors 4 and 4 is indicated bydotted lines along the length of said leads 4 and 4. A small adjustableresistanceo is connected into the lead 4 between the first of saidseries connected discharge devices and the secondary of said transformer'5. The adjustment of said resistance 6 regulates the value of the totalresistance'in the circuit.

,The supply leads 4 are smaller in diameter and the resistance 6 issmaller than would be the case where the current leads 4, 4 were notused as a substantial part of the series connected resistance whichreduces the cost of manufacturing and installing the illuminating systemto a minimum.

In the embodiment of the invention illustrated in Fig. 2 two differenttypes of electric discharge devices are illustrated but it will beunderstood, of course, that in practice only one type of such devicesare used in any given illuminating system. One of the devicesillustrated has a container '7 filled with a gaseous atmosphere similarto that disclosed in connection with the devices of Fig. 1. A thermionicelectrode 9, 10 is sealed into each end of said container. Each of saidelectrodes 9, 10 and 9, 10 comprises an electron emitting cathode part9, which is a coiled nickel or tungsten filament coated or impregnatedwith electron emissive material, such as barium oxide, and an anode part10 which is a metalcylinder, such as a nickel cylinder, surrounding saidcathode 9. Said anode part 10 and said cathode part 9 are connected toeach other by lead 20, as shown. The other of said discharge devicescomprises a container 8, having electrodes 11, 12 sealed therein and agaseous atmosphere therein similar to that of the discharge device firstdescribed. Said electrodes 12 are anodes and said electrode 11 is anelectron emitting cathode similar -to the cathodes 9 and 9.

The discharge devices illustrated in Fig. 2 are connected toauto-transformers 13 and 14 respectively. Said electrodes 9, 10 areconnected 'to sections at the respective ends of said autotransformer 13and cathode 11 is connected to the mid-section of transformer 14. Saidauto-transformers 13 and 14 are less expensive than the usualtransformer having separate coils and further in the case of transformer13 the part thereof between taps 15 and 16 is made of smaller andcheaper wire as said part is not traversed by the operating current.This reduces the total manufacturing cost of the system.

The lead 18 connecting said transformers 13 and 14 in series isconnected to a tap 17 on said transformer 14 between the ends thereofwhich decreases the voltage required to operate this lamp unit whichpermits the connection of a larger number of lamp units into the circuitthan would be possible otherwise. The leads 18 serve as part of theseries resistance as in the embodiment illustratedin Fig. 1. Smallresistances 19 are connected into the leads connecting anodes 12 to theends of the auto-transformer 14 to regulate the discharge current.

A circuit for an illuminating system particu larly useful inilluminating roads, or the like is illustrated in Fig. 3 of the drawing.A two conductor cable is used in this circuit and successive dischargelamp devices are connected to a different conductor as shown. Thecondimtors are each connected to a transformer the primary of which isconnected to a three-phase current supply system having a neutral.- I

It is desirable to provide each lamp unit with a parallelly connectedshunt operated by automatic means controlled by the higher voltageinduced between the terminals of the transformer, or the lamp devicewhen either said transformer, or said lamp device fails. This avoids thefailure of the entire system where one lamp unit fails.

In the circuit of the flluminating system illustrated in Fig. 3 I findit most advantageous to use electric discharge lamp devices filled withsodium vapor and adapted to start on approximately 17.5 volts and tooperate on approximately 13 volts with a discharge current of 6 amperes.

The distance between each lamp device is approximately 40 meters and thenumber of lamp devices is 34'. Each lamp device is connected to anauto-transformer. A voltage of 300 volts is supplied by the secondary ofthe transformer to which the cable connecting the lamp units in seriesis connected. Each of the two leads in each cable is 4 mm in diameterand the resistance thereof is 4.38 ohms/m. Such an illumi-- natingsystem illuminates a section of road 1.4 km. in length. Such a systemrequires a transformer station every 2.8 km. as a section 1.4 km. can beilluminated on each side of said transformer station. The section ofroad illuminated by such an illuminating system can be increased inlength by increasing the number of series connected lamp units and byincreasing the voltage supplied by the main. transformer. i

What we claim as new and desire to secure by Letters Patent of theUnited States is:-

1. An illuminating system comprising a plurality of series connectedgaseous electric are discharge devices eachhaving an electrodecomprising a filament and electron emitting oxide material heatedthereby and a sodium vapor filling, a current source for said systemandan impedance connected in series with each of said devices comprisingthe leads connecting said'devices in series.

2. An illuminating system comprising aplurality of series connectedgaseous electric are discharge devices each-having an electrodecomprising a filament and electron emitting oxide material heatedthereby and a sodium vapor filling, a current source for said system andan im pedance connected in series with each of said devices, 50%-90% ofthe series impedancebeing in the leads connecting said devices inseries.

3. An illuminating system comprising a plurality of seriesconnectedgaseous electric arc discharge devices each having an electrodecomprising a filament and electron emitting oxide material heatedthereby and a sodium vapor filling, a current source for said system andan impedance connected in series with each of said devices, 50%-90% ofthe series impedance being in the leads connecting said-devices inseries and a variable resistance in said series circuit to control thetotal impedance therein.

HENDRIK A. w. AART n1: BRUIN. FERDINANDUS H. A. VAN STEKELENBURG.

